/*
 * Copyright (C) 2005-2006 Alfresco, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */
package org.alfresco.filesys.smb.server;

import org.alfresco.filesys.util.DataPacker;

/**
 * NT Dialect Parameter Packer Class
 * <p>
 * The NT SMB dialect uses parameters that are not always word/longword aligned.
 */
public class NTParameterPacker
{

    // Buffer and current offset

    private byte[] m_buf;
    private int m_pos;

    /**
     * Class constructor
     * 
     * @param buf byte[]
     */
    public NTParameterPacker(byte[] buf)
    {
        m_buf = buf;
        m_pos = SMBSrvPacket.PARAMWORDS;
    }

    /**
     * Class constructor
     * 
     * @param buf byte[]
     * @param pos int
     */
    public NTParameterPacker(byte[] buf, int pos)
    {
        m_buf = buf;
        m_pos = pos;
    }

    /**
     * Pack a byte (8 bit) value
     * 
     * @param val byte
     */
    public final void packByte(byte val)
    {
        m_buf[m_pos++] = val;
    }

    /**
     * Pack a byte (8 bit) value
     * 
     * @param val int
     */
    public final void packByte(int val)
    {
        m_buf[m_pos++] = (byte) val;
    }

    /**
     * Pack a word (16 bit) value
     * 
     * @param val int
     */
    public final void packWord(int val)
    {
        DataPacker.putIntelShort(val, m_buf, m_pos);
        m_pos += 2;
    }

    /**
     * Pack an integer (32 bit) value
     * 
     * @param val int
     */
    public final void packInt(int val)
    {
        DataPacker.putIntelInt(val, m_buf, m_pos);
        m_pos += 4;
    }

    /**
     * Pack a long (64 bit) value
     * 
     * @param val long
     */
    public final void packLong(long val)
    {
        DataPacker.putIntelLong(val, m_buf, m_pos);
        m_pos += 8;
    }

    /**
     * Return the current buffer position
     * 
     * @return int
     */
    public final int getPosition()
    {
        return m_pos;
    }

    /**
     * Return the buffer
     * 
     * @return byte[]
     */
    public final byte[] getBuffer()
    {
        return m_buf;
    }

    /**
     * Unpack a byte value
     * 
     * @return int
     */
    public final int unpackByte()
    {
        return (int) m_buf[m_pos++];
    }

    /**
     * Unpack a word (16 bit) value
     * 
     * @return int
     */
    public final int unpackWord()
    {
        int val = DataPacker.getIntelShort(m_buf, m_pos);
        m_pos += 2;
        return val;
    }

    /**
     * Unpack an integer (32 bit) value
     * 
     * @return int
     */
    public final int unpackInt()
    {
        int val = DataPacker.getIntelInt(m_buf, m_pos);
        m_pos += 4;
        return val;
    }

    /**
     * Unpack a long (64 bit) value
     * 
     * @return int
     */
    public final long unpackLong()
    {
        long val = DataPacker.getIntelLong(m_buf, m_pos);
        m_pos += 8;
        return val;
    }

    /**
     * Reset the parameter packer/reader to use the new buffer/offset
     * 
     * @param buf byte[]
     * @param off int
     */
    public final void reset(byte[] buf, int pos)
    {
        m_buf = buf;
        m_pos = pos;
    }
}